#!/usr/bin/env bash
set -euo pipefail

APP=druk
REPO=letstri/druk

MUTED='\033[0;2m'
RED='\033[0;31m'
GREEN='\033[0;32m'
NC='\033[0m'

usage() {
    cat <<EOF
druk installer

Usage: install [options]

Options:
    -h, --help              Display this help message
    -v, --version <version> Install a specific version (e.g. 0.2.0)
    -b, --binary <path>     Install from a local binary instead of downloading
        --no-modify-path    Don't touch shell config files (.zshrc, .bashrc, …)

Examples:
    curl -fsSL https://druk.sh/install | bash
    curl -fsSL https://druk.sh/install | bash -s -- --version 0.2.0
EOF
}

requested_version=${VERSION:-}
no_modify_path=false
binary_path=""

while [[ $# -gt 0 ]]; do
    case "$1" in
        -h|--help)
            usage
            exit 0
            ;;
        -v|--version)
            if [[ -n "${2:-}" ]]; then
                requested_version="$2"
                shift 2
            else
                echo -e "${RED}Error: --version requires a version argument${NC}" >&2
                exit 1
            fi
            ;;
        -b|--binary)
            if [[ -n "${2:-}" ]]; then
                binary_path="$2"
                shift 2
            else
                echo -e "${RED}Error: --binary requires a path argument${NC}" >&2
                exit 1
            fi
            ;;
        --no-modify-path)
            no_modify_path=true
            shift
            ;;
        *)
            echo -e "${RED}Error: unknown option '$1'${NC}" >&2
            exit 1
            ;;
    esac
done

INSTALL_DIR="${DRUK_INSTALL_DIR:-$HOME/.druk/bin}"
mkdir -p "$INSTALL_DIR"

if [ -n "$binary_path" ]; then
    if [ ! -f "$binary_path" ]; then
        echo -e "${RED}Error: no binary at ${binary_path}${NC}" >&2
        exit 1
    fi
    specific_version="local"
else
    case "$(uname -s)" in
      Darwin*) os="darwin" ;;
      Linux*) os="linux" ;;
      MINGW*|MSYS*|CYGWIN*) os="windows" ;;
      *) echo -e "${RED}Unsupported OS: $(uname -s)${NC}" >&2; exit 1 ;;
    esac

    arch=$(uname -m)
    case "$arch" in
      aarch64|arm64) arch="arm64" ;;
      x86_64|amd64) arch="x64" ;;
    esac

    # Under Rosetta uname says x64 on an arm64 machine; ship the native build.
    if [ "$os" = "darwin" ] && [ "$arch" = "x64" ]; then
      if [ "$(sysctl -n sysctl.proc_translated 2>/dev/null || echo 0)" = "1" ]; then
        arch="arm64"
      fi
    fi

    target="$os-$arch"
    case "$target" in
      darwin-arm64|darwin-x64|linux-arm64|linux-x64|windows-x64) ;;
      *)
        echo -e "${RED}Unsupported platform: $target${NC}" >&2
        echo -e "${MUTED}Supported: darwin-arm64, darwin-x64, linux-arm64, linux-x64, windows-x64${NC}" >&2
        exit 1
        ;;
    esac

    # Default x64 builds need AVX2 (issue #99); MSYS exposes /proc/cpuinfo too.
    case "$target" in
      linux-x64|windows-x64)
        if [ "${DRUK_CPU_BASELINE:-}" = "1" ]; then
            target="$target-baseline"
        elif [ "${DRUK_CPU_BASELINE:-}" != "0" ] && [ -r /proc/cpuinfo ] \
            && ! grep -qw avx2 /proc/cpuinfo; then
            target="$target-baseline"
        fi
      ;;
    esac

    if [ "$os" = "linux" ]; then
        archive_ext=".tar.gz"
        if ! command -v tar >/dev/null 2>&1; then
            echo -e "${RED}Error: 'tar' is required but not installed.${NC}" >&2
            exit 1
        fi
    else
        archive_ext=".zip"
        if ! command -v unzip >/dev/null 2>&1; then
            echo -e "${RED}Error: 'unzip' is required but not installed.${NC}" >&2
            exit 1
        fi
    fi

    filename="$APP-$target$archive_ext"

    if [ -z "$requested_version" ]; then
        url="https://github.com/$REPO/releases/latest/download/$filename"
        # Without the guard, pipefail aborts on curl's exit code before our own error prints.
        latest=$(curl -fsSL --retry 2 "https://api.github.com/repos/$REPO/releases/latest" 2>/dev/null) || latest=""
        specific_version=$(printf '%s' "$latest" | sed -n 's/.*"tag_name": *"v\([^"]*\)".*/\1/p' | head -1)
        if [ -z "$specific_version" ]; then
            echo -e "${RED}Could not find a published release of druk${NC}" >&2
            echo -e "${MUTED}Check https://github.com/$REPO/releases, or install with: npm install -g druk${NC}" >&2
            exit 1
        fi
    else
        requested_version="${requested_version#v}"
        url="https://github.com/$REPO/releases/download/v${requested_version}/$filename"
        specific_version=$requested_version
        if [ "$(curl -sI -o /dev/null -w '%{http_code}' "https://github.com/$REPO/releases/tag/v${requested_version}")" = "404" ]; then
            echo -e "${RED}Error: release v${requested_version} not found${NC}" >&2
            echo -e "${MUTED}Available releases: https://github.com/$REPO/releases${NC}" >&2
            exit 1
        fi
    fi

    if command -v "$APP" >/dev/null 2>&1; then
        installed_version=$("$APP" --version 2>/dev/null || echo "")
        if [ "$installed_version" = "$specific_version" ]; then
            echo -e "${MUTED}druk ${NC}$specific_version${MUTED} is already installed${NC}"
            exit 0
        fi
    fi

    echo -e "${MUTED}Installing ${NC}druk $specific_version${MUTED} for $target${NC}"
    tmp_dir=$(mktemp -d)
    trap 'rm -rf "$tmp_dir"' EXIT
    # curl sizes its progress bar from stdin, which is this script under `curl | bash`.
    curl_stdin=/dev/null
    [ -t 1 ] && [ -e /dev/tty ] && curl_stdin=/dev/tty
    # --retry: GitHub's asset CDN serves transient 502/504s.
    if ! curl -# -fL --retry 3 --retry-delay 1 -o "$tmp_dir/$filename" "$url" < "$curl_stdin"; then
        echo -e "${RED}Failed to download $filename${NC}" >&2
        echo -e "${MUTED}Try again, or check that release v$specific_version carries $target: $url${NC}" >&2
        exit 1
    fi

    if [ "$os" = "linux" ]; then
        tar -xzf "$tmp_dir/$filename" -C "$tmp_dir"
    else
        unzip -q "$tmp_dir/$filename" -d "$tmp_dir"
    fi
    binary_path="$tmp_dir/$APP"
    [ "$os" = "windows" ] && binary_path="$tmp_dir/$APP.exe"
fi

exe_name="$APP"
case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) exe_name="$APP.exe" ;; esac

# mv, not cp: rename(2) works while the old inode is the running druk (cp gets ETXTBSY).
if [ -L "$INSTALL_DIR/$exe_name" ]; then
    echo -e "${RED}Error: $INSTALL_DIR/$exe_name is a symlink; refusing to replace it${NC}" >&2
    echo -e "${MUTED}Remove the symlink and re-run the installer${NC}" >&2
    exit 1
fi

if ! staged=$(mktemp "$INSTALL_DIR/.$exe_name.XXXXXX"); then
    echo -e "${RED}Error: cannot write to $INSTALL_DIR${NC}" >&2
    exit 1
fi
trap 'rm -rf "${tmp_dir:-}" "$staged"' EXIT
cp "$binary_path" "$staged"
chmod 755 "$staged"
mv -f "$staged" "$INSTALL_DIR/$exe_name"

add_to_path() {
    local config_file=$1 command=$2
    if grep -Fxq "$command" "$config_file" 2>/dev/null; then
        return
    elif [ -w "$config_file" ]; then
        printf '\n# druk\n%s\n' "$command" >> "$config_file"
        echo -e "${MUTED}Added druk to \$PATH in ${NC}$config_file"
    else
        echo -e "${MUTED}Add this to $config_file yourself:${NC}"
        echo -e "  $command"
    fi
}

XDG_CONFIG_HOME=${XDG_CONFIG_HOME:-$HOME/.config}

case "$(basename "${SHELL:-bash}")" in
    fish)
        config_files="$HOME/.config/fish/config.fish"
        path_command="fish_add_path $INSTALL_DIR"
    ;;
    zsh)
        config_files="${ZDOTDIR:-$HOME}/.zshrc ${ZDOTDIR:-$HOME}/.zshenv $XDG_CONFIG_HOME/zsh/.zshrc"
        path_command="export PATH=$INSTALL_DIR:\$PATH"
    ;;
    *)
        config_files="$HOME/.bashrc $HOME/.bash_profile $HOME/.profile"
        path_command="export PATH=$INSTALL_DIR:\$PATH"
    ;;
esac

if [ "$no_modify_path" != "true" ] && [[ ":$PATH:" != *":$INSTALL_DIR:"* ]]; then
    config_file=""
    for file in $config_files; do
        if [ -f "$file" ]; then
            config_file=$file
            break
        fi
    done

    if [ -z "$config_file" ]; then
        echo -e "${MUTED}No shell config found. Add this yourself:${NC}"
        echo -e "  $path_command"
    else
        add_to_path "$config_file" "$path_command"
    fi
fi

if [ "${GITHUB_ACTIONS:-}" = "true" ]; then
    echo "$INSTALL_DIR" >> "$GITHUB_PATH"
fi

echo -e ""
echo -e "${GREEN}druk ${specific_version}${NC} installed to ${INSTALL_DIR}"
echo -e ""
echo -e "  druk              ${MUTED}# open the current directory${NC}"
echo -e "  druk ./path       ${MUTED}# open a directory or a file${NC}"
echo -e ""
echo -e "${MUTED}Restart your shell (or source your shell config) if druk is not on \$PATH yet.${NC}"